Question: If $x \circledcirc y = x-3y$ and $x \bigtriangledown y = 3x+y$, find $(1 \bigtriangledown 0) \circledcirc 4$.
Explanation: First, find $1 \bigtriangledown 0$ $ 1 \bigtriangledown 0 = (3)(1)$ $ \hphantom{1 \bigtriangledown 0} = 3$ Now, find $3 \circledcirc 4$ $ 3 \circledcirc 4 = 3-(3)(4)$ $ \hphantom{3 \circledcirc 4} = -9$.